dave_Edwards

I'm just glad to get back to work with Joe---He is a great man and very smart. Dave

Hi Joe, Long time no see---hopefully we can help and teach as much as humanly possable to these guys-----How is CIA doing? If you need anything Email me [email protected] Dave

hello Dave

It's deadened beyond belief. Picking new subs is a hard choice. I think running nothing but horns would work quite well for a while. - Steve 1 Brahma 15 + 3.0 cube tuned to about 25Hz = just a thought Dave

myself----If you didn't build it and don't know what you are doing leave it alone! but if you do know what you are doing----105 degree caps---TO3 output resistors----all that stuff really gets my blood going----to most people a good laid out board---not too much silicone----good weight is a good sign and try to stick to some type of name brand company-----do your homework---check on the amp before you buy---don't just buy it because every other guy has one. Dave

QTS=in simple terms---is it goning to be boomy or smooth sounding Vas=air displacement of the subwoofer Fs=free air resonace BL=flatter the better SPL=how much power is really needed to get them loud xmax=linear movement of the cone RMS=Rarely Means chit---RMS from the manufactor is measured so many ways now a days it doesn't really mean anything. If I have the same sub----one 1.0 cub and one 10.0 cubes-----which box can take more wattage?Right the 1.0 cube-----it is always back to simple physics---smaller air chamber----less air to "pressurize" hope this helps alittle Dave

Prior to 1970, there were no easy or affordable methods accepted as standard in the industry for obtaining comparative data about loudspeaker performance. Recognized laboratory tests were expensive and unrealistic for the thousands of individuals needing performance information. Standard measurement criteria were required to enable manufacturers to publish consistent data for customers to make comparisons between various loudspeakers. Thiele-Small Parameters In the early seventies, several technical papers were presented to the AES (Audio Engineering Society) that resulted in the development of what we know today as 'Thiele-Small Parameters'. These papers were authored by A.N.Thiele and Richard H. Small. Thiele was the senior engineer of design and development for the Australian Broadcasting Commission and was responsible at the time for the Federal Engineering Laboratory, as well as for analyzing the design of equipment and systems for sound and vision broadcasting. Small was, at the time, a Commonwealth Post-graduate Research Student in the School of Electrical Engineering at the University of Sydney. Thiele and Small devoted considerable effort to show how the following parameters define the relationship between a speaker and a particular enclosure. However, they can be invaluable in making choices because they tell you far more about the transducer's real performance than the basic benchmarks of size, maximum power rating or average sensitivity. Fs------This parameter is the free-air resonant frequency of a speaker. Simply stated, it is the point at which the weight of the moving parts of the speaker becomes balanced with the force of the speaker suspension when in motion. If you've ever seen a piece of string start humming uncontrollably in the wind, you have seen the effect of reaching a resonant frequency. It is important to know this information so that you can prevent your enclosure from 'ringing'. With a loudspeaker, the mass of the moving parts, and the stiffness of the suspension (surround and spider) are the key elements that affect the resonant frequency. As a general rule of thumb, a lower Fs indicates a woofer that would be better for low-frequency reproduction than a woofer with a higher Fs. This is not always the case though, because other parameters affect the ultimate performance as well. Re--------This is the DC resistance of the driver measured with an ohm meter and it is often referred to as the 'DCR'. This measurement will almost always be less than the driver's nominal impedance. Consumers sometimes get concerned the Re is less than the published impedance and fear that amplifiers will be overloaded. Due to the fact that the inductance of a speaker rises with a rise in frequency, it is unlikely that the amplifier will often see the DC resistance as its load. Le--------This is the voice coil inductance measured in millihenries (mH). The industry standard is to measure inductance at 1,000 Hz. As frequencies get higher there will be a rise in impedance above Re. This is because the voice coil is acting as an inductor. Consequently, the impedance of a speaker is not a fixed resistance, but can be represented as a curve that changes as the input frequency changes. Maximum impedance (Zmax) occurs at Fs. Q Parameters---------Qms, Qes, and Qts are measurements related to the control of a transducer's suspension when it reaches the resonant frequency (Fs). The suspension must prevent any lateral motion that might allow the voice coil and pole to touch (this would destroy the loudspeaker). The suspension must also act like a shock absorber. Qms is a measurement of the control coming from the speaker's mechanical suspension system (the surround and spider). View these components like springs. Qes is a measurement of the control coming from the speaker's electrical suspension system (the voice coil and magnet). Opposing forces from the mechanical and electrical suspensions act to absorb shock. Qts is called the 'Total Q' of the driver and is derived from an equation where Qes is multiplied by Qms and the result is divided by the sum of the same. As a general guideline, Qts of 0.4 or below indicates a transducer well suited to a vented enclosure. Qts between 0.4 and 0.7 indicates suitability for a sealed enclosure. Qts of 0.7 or above indicates suitability for free-air or infinite baffle applications. However, there are exceptions! The Eminence Kilomax 18 has a Qts of 0.56. This suggests a sealed enclosure, but in reality it works extremely well in a ported enclosure. Please consider all the parameters when selecting loudspeakers. If you are in any doubt, contact your Eminence representative for technical assistance Vas/Cms--------Vas represents the volume of air that when compressed to one cubic meter exerts the same force as the compliance (Cms) of the suspension in a particular speaker. Vas is one of the trickiest parameters to measure because air pressure changes relative to humidity and temperature

Well guys---I read alot of forums and it looks as though ALOT of people are misinformed about the "basics" of car audio----I need your help----tell me a topic in which we can all give our input and see if we can come to learn more-----I personally am sick of seeing these "which sub or which amp" topics----it is called "learn then deside for yourself". I will talk in depth about all of the topics you want but I need a start----you guys from FXN.net know me pretty well to know I can talk for days about car audio. for the guys that don't know me---- http://www.fordexplorer.net/viewforum.php?f=10 Alot of the stickys are mine. Read and enjoy. Live and LEARN, Dave

<----I, myself am not a RF fan but I hope they prove me wrong with the new line they are putting out. Dave

sorry---I was gonna say either Brahma 12 or XXX 12 Either one in a 1.5 cube tuned to about 30hz with that power would make about anyone happy. Dave

well the 1501 can be modded for daily drive @1 ohm----a few resistors and a new set of caps----the 81000d is also a good choice for mods---the only thing is that the heatsink wasn't really made for the higher temps it produces when driven hard daily @ that low of a resistance rating. need any more ideas--email me Dave

Very good young grasshopper-- 90Hz out of the box----it comes with moddable chips---well they will be when I get done with them Dave

Well----I will give my 2cents here if I may----30, you seem cool and all---i personally think your enclosure is cool---but looks kinda rushed---but guess what------that is my opinion----if you like it and it sounds good---cool----as for all the other guys bashing and all----quit---grow up---give the man 15 minutes in the light and let him show you what he did---you know you would be proud of what you built----am I right?----and 30----you are welcome here-----try to add to this forum as much as you did to the others. Thank you, Dave

Well---I got an EQX instead-----sorry----lol Dave

Well----it is easier to just find out for yourself---- http://www.the12volt.com/caraudio/boxcalcs.asp there ya go--- Dave

Thank you all---I sat back on that night and had a Jack and Coke while watching WWE----the wife was out of town---so it wasn't that bad---I got a EQX also Dave

Finally I am getting a Crossover for my system---$150 for a AudioControl 3XS---not bad. just thought I would share

2.25-2.5 cubes tuned to about 30Hz for LOUD SOUND QUALITY applacations---32-34Hz for more of a street vehicle. Hope this helps,

go with the recommended size and tune to a few Hz above the Fs of the sub. That is the way I would do it.

well--I tested a set a few months for Dan Wiggins---the install was the hardest part---they are deep about 3inches or so----they have good weight to them---and I hooked up a Phoenix Gold M100 to them(125 to each speaker)---great off axis responce--and a ton of midbass---for the price you can't get a better sounding set of comps----as for the comparision to the others---yes they "look better" but I will tell you I have Alpine SPX 177a's and I wish I would have bought the Kodas. Dave

use ring Terminal ends on the wire---then just lay them over each other into the amp---alot easier that way. Dave

no---I have heard good and bad about them-----your take on them......

My brother lost the fight of his life on March 11th at 10:45pm---He had been fighting Leukima for 9 years now---it was in remission last week---he went to get a check up and he had a seziure and they admitted him---his temp was 103 that day---the next day they found a ceribral staff infection on the base of his spine----he was on life support for 3 days and he had a living will so @ 7:00 the family had to do the hardest thing in our lives----we had to say good bye to a great and funny man that loved music and his family with all his heart.I never got to hear him say good bye but I know he heard me---I talked with him for at least an hour----he died in Baptist Hopt. in Winston Salem NC--about 2 hours from my house---he loved playing the drums--so---I like to think he is playing in Heavens band. He was only 51 years old, father of one 14 year old son, and 3 year husband to his 2nd wife. Buck Jr.---I love you and I will miss you---- I just thought I would share with you guys..............

wow---another big sub---woop dee doo!I am kinda getting tired of seeing all these new subs that almost outweigh my wife and claim hard to believe numbers---if it can do it---cool if not---chalk up another sub that SS tried and failed at---the SPL series back in the 90's were ok---but that is being nice to them---I just want a test of them(give me one---I'll see what it can take). Dave

how do I put this nice?---NO WAY-----SoundStream isn't bad---but they haven't been the same since they were bought out---I kinda fell off them after the Pure Class A's(which were awesome) The sub---well----hmmm That is something I would have to think about----8500watts RMS?(is that Thermal or mech.?)Oh well but Denim there is NO WAY I would sell any of my PG gear---none---including the MS1000----I will be buried with that thing Dave